A Pilot Study of Additional Chinese Formula for Concurrent Chemoradiotherapy in Oral Cavity Cancer Patients

The goal of this clinical trial is to learn about the clinical efficacy of San-Zhong-Kui-Jian-Tang (SZKJT), a formula of Chinese medicine in head and neck cancer patients receiving concurrent chemoradiotherapy (CCRT) treatments. The main questions it aims to answer are: * Can SZKJT improve the completion rate of CCRT? * Can SZKJT reduce the adverse effects of CCRT? * How SZKJT affect the quality of life in the patients receiving CCRT * How about the safety of using SZKJT in the patients receiving CCRT Participants will be asked to: * take SZKJT for 9 weeks during the whole CCRT course * take questionnaires of quality of life